Tennis: Roddick pounds 21 aces to advance

Having dispatched two teens, the defending champion finally met a seeded veteran in the third round. Something of a challenge, right? Not quite.

Coming close to a perfect serving day, Roddick rolled into the round of 16 by overwhelming No. 29 Guillermo Canas of Argentina 6-1, 6-3, 6-3. Roddick smacked 21 aces, had zero double-faults, and erased all five break points he faced.

Lleyton Hewitt truly was perfect for a set in his 6-1, 6-4, 6-2 victory over No. 30 Feliciano Lopez: The 2001 Open champ won all 16 points on his serve in the first frame.

So far, Roddick has been broken once in 36 service games with totals of 42 aces and three double-faults, going 9-0 in sets.

"I had a game plan, I executed it. I took it to him," said Roddick, who will face No. 18 Tommy Robredo next. "I really don't have a magical explanation for it."

Canas, whose top first serve (126 mph) was slower than Roddick's average (129 mph), provided this succinct analysis: "His serve is difficult. Well, almost impossible."

Serena Williams was nearly as dominant in beating No. 15 Patty Schnyder 6-4, 6-2 to set up yet another Grand Slam quarterfinal against Jennifer Capriati. Williams hit 12 aces, with a lone double-fault, and compiled a 24-9 edge in winners.

She wasn't able to defend her 2002 Open title, missing 8[ months after left knee surgery on Aug. 1, 2003. Doctors advised her to take more time off this summer, including skipping the Olympics and maybe the Open.

"My knee is doing pretty good right now. I haven't had any worries," Williams said. "I'm just excited to be here because I wasn't supposed to come."

Told of those comments, Capriati said: "From now on, I don't believe what anybody says. I just expect them to be 100 percent. Because I really don't think anybody would be playing if they really didn't feel 100 percent."

Capriati weathered a rough patch late to get past No. 12 Ai Sugiyama 7-5, 6-2. Capriati was broken to 5-3, allowing Sugiyama to serve for the opening set, but took four straight games - barely.

Serving while trailing 5-4, Capriati faced a set point, erased when Sugiyama sent a forehand long to end an 18-stroke exchange. Ahead 6-5, Capriati produced her first three double-faults, escaping when Sugiyama missed another forehand.

Capriati's shakiness might not have been forgiven by a stronger opponent. It certainly wasn't in last year's semifinals, when Capriati was two points from victory 10 times against eventual champion Justine Henin-Hardenne.

And now Capriati faces Williams, ahead 10-6 in their head-to-head matches. It's the third straight major where they'll meet in the quarterfinals: Capriati won at the French Open, Williams won at Wimbledon.

"I've played her at her best. I've played her at her worst," Capriati said. "I've played her at my best, me at my worst. I can just only worry about myself, really."

No. 10 Vera Zvonareva had just about everyone at Louis Armstrong Stadium a bit concerned about her during a 1-6, 6-4, 6-3 loss to No. 6 Elena Dementieva.

Even while leading, Zvonareva appeared distraught. She wiped away tears between points, she cried into a towel during changeovers, she whacked herself in the foot with her racket, she cracked her racket on the court, on her chair, on her bag.

"When I'm comfortable with my tennis, when I know what I'm doing on the court and when I play for every ball," Zvonareva said, "then I don't get like this."

After a sublime first set, she was downright awful, finishing with 12 double-faults and 63 unforced errors (53 in the last two sets). That allowed Dementieva to advance despite only 12 winners. She can earn her second trip to the Open semifinals by defeating No. 2 Amelie Mauresmo, a 6-4, 6-2 winner over No. 19 Francesca Schiavone.

Like Williams, Tommy Haas missed the 2003 Open because of surgery - his right shoulder was operated on twice. Pain-free and playing superbly, Haas reached the fourth round with a 6-2, 6-3, 7-5 victory over qualifier Ricardo Mello.

Haas' next opponent is 18-year-old Tomas Berdych of the Czech Republic, who eliminated Mikhail Youzhny 2-6, 6-1, 6-3, 4-6, 6-1. Berdych stunned Roger Federer at the Olympics, giving him the same number of victories over the No. 1 player as Roddick owns: one.

But the way Roddick's serving at the National Tennis Center, he might deserve the tag of favorite if there's a 1-vs.-2 final the way there was at Wimbledon.

In the opening game against Canas, Roddick faced two break points. He saved one with a violent forehand, the other with a second serve that drew a long return. Roddick then settled down, dropping a total of six points in his next six service games.

Facing his first break points in 50 minutes, ahead 4-3 in the second set, Roddick spun in an 89 mph second serve that Canas put into the net.

"That was a big relief for me," Roddick said.

There was one last test, at 2-2 in the third. Facing two break points, Roddick revved up and slammed aces at 134 mph, 136 mph and 142 mph. Not enough to break the tournament record of 152 mph he set in his first match and tied in his second, but effective nonetheless.